Concrete building structure



W. E. NELSON CONCRETE BUILDING STRUCTURE June 23, 192 5. 1,543,509

Filed NOV. 15, 1922 5 Sheets-Sheet 1 June 2 3, 1925. 1,543,509

W. E. NELSON CONCRETE BUILDING STRUCTURE Filed Nov. 15, 1922 5 Sheets-Sheet 2 June 23, 1925. 1,543,509

W. E. NELSON CONCRETE BUILDING STRUCTURE Filed Nov. 15, 1922 3 Sheets-Sheet 5 avwewtoz wmmm f. A2280 Patented June 23, 1925.

UNITED STATES WILLIAM E. NELSON, or WASHINGTON, DISTRICT or COLUMBIA.

CONCRETE BUILDING STRUCTURE.

Application filed November 15, 1922. Serial No. 601,186.

To all whom it may concern:

Be it known that 1, WILLIAM E. NnLsoN'. a citizen of the United States, residing at Vashington, District of Columbia, have'invented certain new and useful Improvements in Concrete Building Structures; and I do declare the following to be a full, clear, and exact description of the inventionfsuch as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to concrete structures such as buildings, silos, culverts, etc, and particularly to an improved concrete building construction.

Concrete building structures at the present time are either of the molded type called monolithic constructions, or are made of molded concrete blocks laid up in mortar or cement. The latter type of construction produces a weak wall and is expensive because skilled labor must be employed to erect it. While the monolithic construction is much stronger and has come into more extensive use,-it is likewise expensive to erect because molds or forms must be made by skilled labor and much time is consumed in erecting and removing such forms.

The primary object of my invention is to build monolithic concrete structures without the use of forms or molds, in about one-fourth the time now required to erect such structures and at a saving of approximately forty per cent of the total cost of the structures. This is accomplished mainly by utilizing a part of the wall for the form, thereby eliminating the expense of and the skilled labor necessary to erect the usual forms. Briefly stated, my invention contemplates the use of pre-cast units of concrete which constitute approximately two-thirds of the wall and create the form for the other one-third, which is poured immediately around the reinforcing steel placed in the deep grooves formed in the opposed edges of the pre-cast units. These units are of standard size and are made at a plant by pouring a rather lean concrete mixture into sectional molds. They are de livered on the job the same as would be lumber used for making the usual forms for monolithic concrete structures, and they are set in place by common labor, no mortar being used in setting the units and they may be put in place with much greater speed and accuracy by unskilled labor than the average building block or unit of natural stone, burnt clay, etc. can be placed by a mason. The pre-cast units are arranged edge to edge in vertical columns and horizontal rows so that the deep grooves in their four'edges form vertical and horizontal mold passages which are in communication and into which a rather rich mixture of liquid cement is poured to form a monolithic skeleton frame-work of parallel columns or pillars and parallel beams Wl'll'Cll comprise approximately one-third of the complete structure. The proportions of the pre-cast units and their grooves is such .that they may be placed upon each other build a concrete structure flexible enough to take care of contraction and expansion and in which the reinforcing steel is effectively protected from corrosion and deterioratlon. It is a well known fact that concrete such as is generally used in concrete structures, is not water-proof and when the concrete is used for housing Water, a great deal of trouble is experienced in protecting the steel, as the water will penetrate the concrete and corrode the steel unless the concrete is a very rich mixture such as one part cement to one and one-half parts sand. Such a mixture is expensive and is also much more susceptible to temperature cracks than a lean mixture. Itis common practice to keep steel six inches from the surface in all concrete structures which are used for housing water if it is near the surface of the concrete moisture may reach it through the temperature cracks even if the concrete is rich enough to be water-proof. By my method the steel may be laced within one inch of the surface and e perfectly protected, since the pre-cast units are made of a comparatively lean mixture while the poured columns and beams in which the steel is embedded are made of water-proof concrete. This rich portion of the wall is protected from the elements by the leaner mixture which is on the outside of it and which will not temperature crack. This waterproofing of the steel may be made more perfect by coating the deeply grooved edges of the pre-cast units with an ordinary cement Water-proofing and cement bonding compound Which .completely surrounds the poured columns and beams and which insures a perfect chemical bond between the poured portion and the pre-cast units ofthe structure. This elastic bonding compound is put on the pre-cast units before they are delivered on the work and it eliminates the necessity of keeping the units wetted while the Work is being poured. The use of this elastic bonding compound in connection with the use of relatively small pre-cast concrete units which are preferably twelve inches square insures a structure of sufii cient flexibility to take care of contraction and expansion without the necessity of in serting the usual expansion joints.

The above and other objects of the invention as will hereinafter more fully appear, are accomplished by the constructions illustrated in the accompanyingdrawings, in which:

Figure 1 is a perspective view of a cornerview taken on the plane indicated by the line 33 of Fig. 5.

Figure 4 is a detail sectional view show ing the application of the bonding compound to the grooved edges of the pre-cast units.

tional view on the plane indicated by the line 5-5 of Fig. 3.

Figure 6 is a horizontal sectional view of a curtain Wall and column construction taken on the plane indicated by the line 6-6 of Fig. 7.

Figure 7 is a front elevation of a curtain Wall and column construction embodying the principles of the invention.

Figure 8 is a horizontal sectional view of a Wall and pilaster construction embodying the principles of the invention.

Figure 9 is a side elevation of the construction shown in Fig. 8.

Figure 5 is a vertical longitudinal sec,-

Figure 10 is a perspective view of a curved wall constructed according to the invention, said view illustrating a number of the pre-cast units brokenaway and some of them removed so as to show a portion of the monolithic framework.

Figure 11 is a horizontal sectional view of a portion of the curved wall shown in Fig. 10.

Figure 12 is a. plan view of the upper edge of one of the pre-cast units which are used in the erection of the curved wall illustrated in Figs. 10 and 11.

Figure 13 is a view of the rear or inner side of one of the pre-cast units which are shown in Figs. 10, 11 and 12. I

The pre-cast units used in carrying out my method are made of a rather lean con-, erete mixture and may be produced rapidly and at small expense by pouring the mixture into multiple, sectional molds, allowing it to set either with or without the application of heatand then allowing the units to season at the plant before delivering them on thejob. The fact that the units are poured or cast makesthem less expensive and stronger than the usual dry-tamped concrete building block. 'hile they may be made in different sizes. I have found in practice that standard units twelve inches by twelve inches by six inches are the most effective for obtaining the desired results but I do not limit myself to these dimensions. In the accompanying drawings I have illustrated two principal standard units which are all of the same standard proportions but differ slightly due to their different uses. These two types of units are designated by the numerals 1 and 1. The units 1 are intended to be used in the erection of straight walls or similar structures. and the units 1' are intended to be used in the erection of curved walls or similar structures. All of the units 1 and 1 are solid. are preferably of square or substantially rectangular shape and are provided at all of their edges with comparatively wide and deep semi-circular grooves 2. The units are preferably about one-half as thick as they are long and high, and the grooves 2 are slightly less in width than the thickness of the units. This proportioning is important since it permits of the effective pouring of the liquid concrete at points remotely spaced from each other into a large number of superimposed courses of units simultaneously, thus saving much time in the erection of the structure.

The units 1 have all four of their edges cut off at right angles to their inner and outer surfaces so that the inner and outer faces are of exactly the same shape and size. The units '1 have their inner faces as h gh as their outerfaces but such inner faces are shorter in length than the outer faces so that the vertical side edges of the units are really disposed angularly with respect to their inner and outer faces.

After the units have been allowed to season in a drying yard or shed at the plant and before they are delivered at the job or place where the concrete structure is to be erected, the grooved edges 2 of the units are painted with a coat 2 of a suitable 'ater-proof and elastic bonding compound with which the poured liquid cement will unite. This bonding compound also tends to prevent leakage of the liquid concrete when it is poured.

To erect a wall or similar construction out of units 1 or 1 according to the present invention, the units are intended to be first set upedge to edge without the use of mortar and with the inner and outer portions of their edges contacting so as to arrange them in parallel courses and also in parallel columns with the side edgcs'of the superimposed units arranged in alinement. This arrangement of the units permits quick erection by unskilled labor since no binding cement or mortar is used. The intent on is to erect or build up a structure out of the units of approximately the height. of one story of a building so that the grooves 2 in the edges of the units will form in such structure a network of laterally closed intersecting passages having substantially horizontal and approximately upright portions. In these passages which are laterally closed because the edges of the adjacentunits contact.liquid concrete is molded without the use of forms or mold boards. Since the units are of small uniform size and it is not necessary to laythcm in mortar, they may be set up by common labor with a great deal more speed than a skilled mason can lay up in cement or mortar the usual build ing blocks or units. Since no forms are needed, the services of skilled carpenters are also dispensed with.

After the structure has been built up to the desired height. or to a considerable height, ap n'oximately ten courses or about the height of one story of a building, the network of passages is tilled with liquid concrete. This. according to theinvention, is preferably done by pouring the liquid concrete into the passages at the top of the structure so that it will flow downwardly and laterally and till all portions of the whole. network of passages. After that has been done. it of course is the intention to permit the liquid concrete to set in the network of passages. The pouring of the liquid concrete is intended to be done at considerably spaced intervals around the top of the structure formed by the pre-cast units and that would depend upon the shape and character of the structure. For example, a wall eight feet high may be poured at intervals of eight feet along the top thereof but in some cases the pourings may be at much greater distances. A circular silo of thirty feet diameter has been poured at two diametrically opposite points. It may, of course, be poured by hand or machinery as is now done in large operations. The relatively short length of the units together with the relatively large diameters of the grooves 2 in the units insures the complete filling of all portions of the network of passages since the liquid concrete will flow readily through the horizontal portions of the network.

The liquid concrete when set or hardened in the network of passages forms a monolithic skeleton framework of intersecting parallel columns or pillars 3 and parallel beams 4. These pillars and beams are preferably of circular shape in cross-section and of uniform cross sectional area throughout. This monolithic framework of pillars and beams gives to the structure great strength which is. of course. supplemented by the precast nuts. The latter serve as facing blocks in the completed structure. while during erection. they serve as molds or forms. thus doing away with the expense of the forms as well as the cost of skilled labor in erecting and removing such forms.

In Fig. 1 of the drawings. there is illustrated a corner construction formed by two straight walls A and B erected as hereinbefore described out of pre-cast units 1 and a monolithic framework of pillars 3 and beams 4. These two walls A and B, are arranged at right angles to each other as shown in Figs. 1 and .2 so as to form a corner recess at the place where they meet. This recess has its inner sides bounded by the grooves 2 of the corner units 1. It is intended to be filled with liquid concrete at the time the network of passages in the walls A and B are filled, so as to form a corner column 5. In order to form this corner column mold boards 6 must be used so as to define the shape of the outer sides of the column 5. This construction obviates the necessity of special corner blocks or units.

In order to reinforce the monolithic framework, reinforcing rods 7 are embedded in the parallel beams 4. These rods 1 which are preferably of steel, extend longitudinally though the beams 4 and are located adjacent the lower sides thereof as shown. It is simply necessary to lay these rods 7 in the grooves 2 since the semi-circular cross sectional shape of the latter will cause the rods to be centered at the lowest points of the grooves where they will be of greatest value in reinforcing the molded beams 4. Since no tying or fastening of the rods 7 is necessarv. this portion of the erection is simplified ant cheapcncd. The pillars 3 are also reinforced preferably by pairs of steel rods 8. These rods 8 extend longitudinally through the pillars 3 and are disposed on opposite sides of the central or neutral axes of said pillars adjacent the inner and outer sides thereof and pass the rods 7 on opposite sides of the latter. This arrangement of the rods 8 insures their greatest reinforcing value in the pillars 3 and also obviates the need of tying them since when the liquid concrete is poured it will naturally force them in opposite directions against the curved walls of,

the vertical portions of the grooves in the units if they are initially dropped intosubstantially correct positions. The corner column 5 is provided with a plurality of upright metal reinforcing rods 9 and the horizontal reinforcing rods 7 which are embedded in the various beams disposed in the walls A and B extend into the corner column 5 and have their ends arranged in crossed or overlapping relation.

The above described system of reinforcing the monolithic framework is important for it insures a maximumamount of reinforcing at the points where it is needed the most. The concrete of the pillars 3 is relied upon to resist compression, while the rods 8 and the concrete between such rods and the outer sides of the structure are relied upon to resist tensile strain. The .rods 8 being located adjacent the inner and outer sides of the pillars 3 take care of the known fact that when pressure is applied to a wall, the side of the wall opposite the. side where pressure is applied will be put under tension while the side upon which the pressure is exerted will be put under compression.

\Vhere it is desired to erect a wall section such as (J at right angles to the intermediate portion of the wall A as shown in Fig. 2, the inner edges of the units 1 in a pair of adjacent columns of units of the wall A should be chipped or cut away so as toprovide a lateral opening into the passage defined by the grooves 2 in the edges of the units. The wall section C can then be erected out of pre-cast units 1 so that the grooves 2 in the endmost column of units will be disposed over this lateral opening. Then, when the liquid concrete is poured, a columnclQ disposed in the passage formed'by the grooves in the units of the wall A which have their inner portions of one of their edges broken or cut away, the lateral opening into this passage and the passage formed by the grooves at the end edges of the end column of units in the wall section C will be formed. The reinforcing rods 7 in the horizontal beams 4 of the wall section C may have their ends extending into the column 10 and in crossed relation to the rods 7 which extend through the beams 4 of the wall section A.

In Fig. 2, a wall section D is shown arranged angularly to the intermediate portion of the wall section A. This may be erected in the same general manner as the wall section C is erected, but in View of the fact that the section D is arranged angularly to the wall A, a mold board 11 must be used to bridge the space between the wall A and that edge of the endmost column of units 1 in the wall section B that is spaced from the'wall A.

Instead of using the mold boards in the erection of a curtain wall, specially constructed pre-cast concrete units 19 may be used. These units 19, shown in Figs. 6 and 8 are intended to be used in pairs. The opposing sides of the units of each pair are provided with large semi-circular recesses 20 so as to form large circular columns 21. In order that thecolumns 21 will be integrally united with the various pillars 3 and beams 4 of the wall sections formed by the pre-cast units 1, the units 19 are provided with passages 22 which extend from their recesses 20 so as to communicate with the horizontal passages formed in the wall sections madeup of the pre-cast units 1.

A pilaster, such as shown in Fig. 8 of the drawings and represented by the numeral 23, may be formed integrally with the pillars 3 and beams 4 of a wall section made up of the pre-cast units 1 by the use of precast concrete units 25 such as shown in Figs. 8 and 9. In such case, the inner edges of adjacent intermediate columns of the units 1 should be chipped or broken away so that the pilasters 23 will be integrally united with the adjacent pillars of the wall section when the liquid concrete is poured.

In Figs. 10, 11 and 12 of the drawings, a curved wall .made up of a plurality of the pre-cast units 1 is illustrated. The beams 4 of the monolithic framework of this wall are reinforced with curved metal rods 26. Other than this, the curved wall is constructed the same as the hereinbefore described straight walls.

By making the poured portion of the structure of a rich mixture of cement and sand, the enclosed reinforcing steel is pro tected from corrosion and this water-proofing may be made more effective by coating the grooved edges of the pre-cast units with the above mentioned bonding compound. The use of the latter in connection with the small size of the pre-cast units give the wall suflicient flexibility to take care of all expansion and contraction so that special expansion inserts or joints are unnecessary. IVhile the rich mixture of the poured portion of the wall is more susceptible to temperature cracks, it is in my method protected by the leaner mixture of the pre-cast units which surround it and which will not temperature crack. The use of the elastic water-proof bonding compound also eliminates theneed of wetting the grooved edges of the units prior to the pouring opera tion and insures a perfect chemical bond between the two portions, thus making a I monolithic structure.

From the foregoing it will be seen that my method permits the erection of a strong and durable monolithic concrete structure in an easy, quick and inexpensive manner b common labor. In practice, I have been a le to erect a reinforced monolithic concrete wall by common labor in about onefourth the time now required to erect an equivalent wall with forms and skilled labor, and at a saving of approximately forty per cent in the total cost of the wall. My system is of special value on the farm where it is usually difficult and expensive to get skilled labor, since the farmer may purchase the units and with common labor erect houses, barns, silos, culverts, water-tanks and the like.

The herein described wall construction and the corner construction shown in Figs.

1 and 2, are described and claimed in my pending application Serial No. 421,139, filed November 1, 1920, which is a continuae tion of my abandoned application Serial No. 296,595, filed May 12, 1919, and a substitution for my-abandoned application Serial No. 343,507, filed Dec. 9, 1919.

I claim:

1. An article. of manufacture comprising a concrete building unit having grooves in its edges to register with grooves of other units and receive a liquid core forming concretelmixture, and a dried coating of elastic bonding compound on the edges of said unit for tight contact with the coatings of other units. 2. A monolithic concrete wall comprisin a plurality of concrete units laid upon eac Y other to form a pillar,'said units having vertically alined recesses to receive a concrete core, and a plurality of concrete wall units contacting with said pillar forming units, said wall units having recesses in communication with the recesses of said pillar forming units, and a concrete core filling all of said recesses and tying all of said units together.

3. A monolithic concrete wall comprising a plurality of? concrete units laid in tiers to form a pillar, each tierconsisting of a aflixed my signature.

WILLIAM E; NELSON.

'pair of opposed units provided with register-' 

